Automatic let-off motion for looms.



No. 755,011. PATENTEDMAR. 22," 1.904'.

J. A. JANSSON.

AUTOMATIC LET-OFF MOTION FOR Looms.

APPLICATION FILED NOV. 12, 1901.

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,UNrTnD STATES Patented. March 22, 1904.

J OHAN AUGUST JANSSON, OF STOCKHOLM, SWEDEN.

AUTOMATIC LET-OFF MOTION FOR LOONIS.

SPECIFICATION forming part of Letters Patent No. 755,011, dated March 22, 1904.

Application filed November 12, 1901. Serial No- 82,014. (No model.)

To all whom, it may concern:

Be it known that I, J OHAN Aueusr J ANSSON, manufacturer, a subject of the King of Sweden and Norway, and a resident of Hagalund, Stockholm, in the Kingdom of Sweden, have invented certain newand useful Improvements in Automatic Let-Off Motions for Looms, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to an automatic letoff motion for looms; and it consists in the combination and arrangement of parts hereinafter described, and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 shows the device in a side view, and Fig. 2 the same viewed from the back of the loom.

1 is the warp-beam, 2 a shaft journaled parallel to the latter, and 3 a whip-roll parallel to the shaft, to which it is connected by means of arms 4. The warp 5 passes from the beam upward beneath the shaft, over the whip-roll, and farther toward the front, as shown in Fig. 1. The shaft 2 is at the side of the loom provided with a downwardly-pointing lever 6, between which and some fixed point on the loom is stretched a spiral spring 7 counteracting the torque exerted by the warp on shaft 2 and arm 6 owing to the upward direction of the arms 4. The shaft 2 and whip-roll 3 thus form a kind of tension-beam, while the spring serves to bring about the tension. The tension of the spring may be adjusted as required by turning the nut 8, and the spring can .be shifted on the lever 6 by moving the sliding collar 9, to which it is attached, said collar being secured by a set-screw or the like. The tension of the warp thus can be accurately adjusted. The escapement-wheel 10 is journaled on the loom close to the lower end of lever 6 and is geared to the warp-beam 1 by means of the pinion 11 and gear 12. The double pawl 13, likewise pivoted in the loom, engages with the escapement-wheel 10 and is provided with an upwardly-pointing projection 14. The lever 6 is provided at the inside with a projection 15 in the shape of an angle-iron, stud, or the like, which when the lever 6 moves to the right strikes the projection 14 of the pawl 13,

.15 of the lever.

thereby bringing the left end of the latter out of engagement with the escapement-wheel.

The mechanism operates as follows: In consequence of the tension of the warp and the presence of the gearing the wheel 10, checked by the pawl 13, strives to rotate in the direction of the arrow, Fig. 1. In the progress of the weaving operation the tension or resistance of the warp increases. This causes a swinging ofthe lever 6 to the right and eventually a disengagement of the pawl 13 by the latter being struck by the projection Striking the pawl is done with a light blow, due to the lever-arm 6, while weaving is going on, having an oscillating movement in its progressing motion to the right. The escapement-wheel 10 thus released now revolves one tooth, or through a certain angle, and a corresponding piece of the warp is unwound or let off from the beam. The lever-arm 6 simultaneously advances to its starting position owing to the decreasing tension of the warp and in consequence of the tension of the spring 7. The fact that the wheel .10 only revolves a single tooth or through a certain angle is due to the right end of the released pawl striking the revolving wheel, so-

that the pawl is made to swing back and again engage and check the wheel with its left end. In this manner the advantage is gained that the tension of the warp never exceeds that corresponding to the adjustment of spring 7, and as a result the web retains the same width and density throughout its entire length. As evident from the drawings, the pendulum-lever 6 acts upon the pawl 13 only at the moment when disengagement takes place, the pawl subsequently automatically dropping into and checking the wheel 10 without being touched by the lever. This is an important advantage as compared with the tension devices hitherto employed, in some cases likewise provided with levers, pawls, and the like, since partly the pawl is not dependent on the lever 6 in its return motion to the position in which it checks the wheel, inaccuracies which might otherwise easily arise in the working of the mechanism being thereby avoided, and partly the pawl is allowed to rest perfectly undisturbed in its checking position until being disengaged by a light'blow of the lever. The wear of the wheel-teeth and pawl is thus reduced to a minimum. The tension of the spring 7, moreover, is very easily controlled in consequence of the convenient arrangement of the spring, as may be readily understood from the drawlngs.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is 1 l. The combination of the warp-beam, an escapement-wheel 1O retaining the same, the double pawl 13, engaging said escapementwheel and being provided with a projection 14, a whip-roll 3, a shaft therefor and a pendulum-lever 6 hanging down from said shaft and having a lateral projection 15, thereon, a spring 7 being connected with said lever for keeping the warp in tension, the projection 14 of the pawl being in the path of the projection 15, whereby the disengagement of the escapement-wheel 10 is effected.

2. In an automatic let-off for looms, the combination with the frame and warp-beam journaled therein, a shaft journaled parallel thercwith, a tension-bar having arms connecting it to said shaft, an arm depending from said shaft, an escapement-wheel journaled in the frame in proximity to the end of said arm, gearing connecting said wheel with the warpbeam, a double pawl on the frame engaging with the escapement-wheel and having an abutment, a projection or abutment on said arm adapted to strike the abutment on the pawl and an adjustable spring for exerting tension on said arm, substantially as described.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

J OHAN AUGUST JANSSUN.

Witnesses:

ERNST SVANGVIST, A. F. LUNDBORG. 

